A Thin Film Transistor-Liquid Crystal Display (TFT-LCD) includes a color filter substrate, an array substrate, and a liquid crystal layer filled in between the color filter substrate and the array substrate. Due to contraction or expansion of volume of liquid crystal molecules with changes of temperature, and a vacuum sealed structure of a liquid crystal panel, vacuum bubbles in a low temperature state or gravity defect in a high temperature state may occur to the liquid crystal panel. Accordingly, it is stipulated in the fabrication process of the liquid crystal display that a liquid crystal filling range allowed in which no vacuum bubble at a low temperature or gravity defect at a high temperature occurs is referred to as a liquid crystal amount range.
In order to control uniformity of thickness of the liquid crystal layer, that is, to ensure a liquid crystal layer margin to be uniformly distributed in the liquid crystal panel, a layer of elastic Post Spacer (PS) is disposed between the color filter substrate and the array substrate in the prior art, for supporting the color filter substrate and the array substrate and for maintaining spacing between the two, to avoid mutual dislocation of the color filter substrate and the array substrate or defects such as light leakage, uneven image quality caused by failure of timely restoration of the spacing of the liquid crystal panel, when the panel with a closed structure is subject to an action of external force.
In the prior art, there are at least problems as described below: when the liquid crystal is affected by temperature to contract too much, rendering the liquid crystal layer margin exceeding a lower limit, and when a deformation amount of the PS reaches a certain extent that cannot satisfy a contraction amount of the liquid crystal due to a limited elasticity of the PS, the further contracted liquid crystal will form vacuum bubbles between the color filter substrate and the array substrate, and as a result, the display cannot display normally; when the liquid crystal is affected by temperature to expand too much, rendering the liquid crystal layer margin exceeding an upper limit, due to expansion force of the liquid crystal, the spacing between the color filter substrate and the array substrate is increased and a volume of the PS shrinks, that is, spacing occurs between the PS and the array substrate in their original contact position, so that space where the liquid crystal is located becomes large; as a result, the liquid crystal slides down under an action of gravity, and gravity defect occurs. To avoid the above-described problems, it is necessary to strictly control the amount of liquid crystal instilled into the liquid crystal panel to be within the liquid crystal amount range; however, since the liquid crystal amount range is relatively small, it is difficult to control during a fabrication process.